UNITED NATIONS, Sept. 21, 2019 (Xinhua) -- United Nations Secretary-General Antonio Guterres (R) speaks during the UN Youth Climate Summit at the UN headquarters in New York, Sept. 21, 2019. UN Secretary-General Antonio Guterres on Saturday said he saw a change in the momentum of global climate action thanks to the ongoing youth movement. (Xinhua/Li Muzi/IANS)